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African HIV/AIDS trials are more likely to report adequate allocation concealment and random generation than North American trials.

Siegfried N, Clarke M, Volmink J, Van der Merwe L - PLoS ONE (2008)

Bottom Line: Using univariate and multivariate logistic regression analyses we evaluated the association between location (Africa versus North America) and these domains.Additional significant factors positively associated with quality were an a priori sample size power calculation, restricted randomization and inclusion of a flow diagram detailing attrition.We did not detect an association between location and outcome assessor masking.

View Article: PubMed Central - PubMed

Affiliation: Clinical Trial Service Unit, University of Oxford, Oxford, United Kingdom. nandi.siegfried@mrc.ac.za

ABSTRACT

Background: Adherence to good methodological quality is necessary to minimise bias in randomised conrolled trials (RCTs). Specific trial characteristics are associated with better trial quality, but no studies to date are specific to HIV/AIDS or African trials. We postulated that location may negatively impact on trial quality in regions where resources are scarce.

Methods: 1) To compare the methodological quality of all HIV/AIDS RCTs conducted in Africa with a random sample of similar trials conducted in North America; 2) To assess whether location is predictive of trial quality. We searched MEDLINE, EMBASE, CENTRAL and LILACS. Eligible trials were 1) randomized, 2) evaluations of preventive or treatment interventions for HIV/AIDS, 3) reported before 2004, and 4) conducted wholly or partly (if multi-centred) in Africa or North America. We assessed adequacy of random generation, allocation concealment and masking of assessors. Using univariate and multivariate logistic regression analyses we evaluated the association between location (Africa versus North America) and these domains.

Findings: The African search yielded 12,815 records, from which 80 trials were identified. The North American search yielded 13,158 records from which 785 trials were identified and a random sample of 114 selected for analysis. African trials were three times more likely than North American trials to report adequate allocation concealment (OR = 3.24; 95%CI: 1.59 to 6.59; p<0.01) and twice as likely to report adequate generation of the sequence (OR = 2.36; 95%CI: 1.20 to 4.67; p = 0.01), after adjusting for other confounding factors. Additional significant factors positively associated with quality were an a priori sample size power calculation, restricted randomization and inclusion of a flow diagram detailing attrition. We did not detect an association between location and outcome assessor masking.

Conclusions: The higher quality of reporting of methodology in African trials is noteworthy. Most African trials are externally funded, and it is possible that stricter agency requirements when leading trials in other countries and greater experience and training of principal investigators of an international stature, may account for this difference.

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Flow diagram of eligibility selection process for North American trials.
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pone-0003491-g001: Flow diagram of eligibility selection process for North American trials.

Mentions: The hand-searchers identified 2,456 records as randomized trials and 785 of these were judged eligible by the first author (Figure 1). We then selected the first 150 of the randomly sorted 785 records, which yielded 116 discrete North American trials. Ninety-six trials were based exclusively in the US, six exclusively in Canada, and 14 were multinational trials including sites either in Canada or the US, or both. No trials from Greenland were found. The distribution of key trial characteristics in the included sample was similar to that in those records that were excluded from the overall dataset (see Table 5), indicating a representative sample.


African HIV/AIDS trials are more likely to report adequate allocation concealment and random generation than North American trials.

Siegfried N, Clarke M, Volmink J, Van der Merwe L - PLoS ONE (2008)

Flow diagram of eligibility selection process for North American trials.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2566805&req=5

pone-0003491-g001: Flow diagram of eligibility selection process for North American trials.
Mentions: The hand-searchers identified 2,456 records as randomized trials and 785 of these were judged eligible by the first author (Figure 1). We then selected the first 150 of the randomly sorted 785 records, which yielded 116 discrete North American trials. Ninety-six trials were based exclusively in the US, six exclusively in Canada, and 14 were multinational trials including sites either in Canada or the US, or both. No trials from Greenland were found. The distribution of key trial characteristics in the included sample was similar to that in those records that were excluded from the overall dataset (see Table 5), indicating a representative sample.

Bottom Line: Using univariate and multivariate logistic regression analyses we evaluated the association between location (Africa versus North America) and these domains.Additional significant factors positively associated with quality were an a priori sample size power calculation, restricted randomization and inclusion of a flow diagram detailing attrition.We did not detect an association between location and outcome assessor masking.

View Article: PubMed Central - PubMed

Affiliation: Clinical Trial Service Unit, University of Oxford, Oxford, United Kingdom. nandi.siegfried@mrc.ac.za

ABSTRACT

Background: Adherence to good methodological quality is necessary to minimise bias in randomised conrolled trials (RCTs). Specific trial characteristics are associated with better trial quality, but no studies to date are specific to HIV/AIDS or African trials. We postulated that location may negatively impact on trial quality in regions where resources are scarce.

Methods: 1) To compare the methodological quality of all HIV/AIDS RCTs conducted in Africa with a random sample of similar trials conducted in North America; 2) To assess whether location is predictive of trial quality. We searched MEDLINE, EMBASE, CENTRAL and LILACS. Eligible trials were 1) randomized, 2) evaluations of preventive or treatment interventions for HIV/AIDS, 3) reported before 2004, and 4) conducted wholly or partly (if multi-centred) in Africa or North America. We assessed adequacy of random generation, allocation concealment and masking of assessors. Using univariate and multivariate logistic regression analyses we evaluated the association between location (Africa versus North America) and these domains.

Findings: The African search yielded 12,815 records, from which 80 trials were identified. The North American search yielded 13,158 records from which 785 trials were identified and a random sample of 114 selected for analysis. African trials were three times more likely than North American trials to report adequate allocation concealment (OR = 3.24; 95%CI: 1.59 to 6.59; p<0.01) and twice as likely to report adequate generation of the sequence (OR = 2.36; 95%CI: 1.20 to 4.67; p = 0.01), after adjusting for other confounding factors. Additional significant factors positively associated with quality were an a priori sample size power calculation, restricted randomization and inclusion of a flow diagram detailing attrition. We did not detect an association between location and outcome assessor masking.

Conclusions: The higher quality of reporting of methodology in African trials is noteworthy. Most African trials are externally funded, and it is possible that stricter agency requirements when leading trials in other countries and greater experience and training of principal investigators of an international stature, may account for this difference.

Show MeSH
Related in: MedlinePlus